TW201635273A - Recovery method and device for close range acoustic wave - Google Patents

Abstract

Recovery method and device for close range acoustic wave are provided. The method includes: generating at least one acoustic signal; generating at least two high-frequency carrier wave signal corresponding to the acoustic signal; embedding the acoustic signal to each corresponded carrier wave signal; and transmitting the carrier wave signal to an overlapped area to form a close-range recovered acoustic wave. The close-range recovered acoustic wave has high directivity and can be heard only in the overlapped area; thereby a close range appreciation space free from outside interference is formed.

Description

Short-distance fixed-point reduction sound wave forming method and device

The invention relates to a method and a device for forming a short-distance fixed-point reduction sound wave; in particular, a method for loading an audio signal by using a high-frequency carrier signal to form a loading signal, and superimposing a plurality of loading signals on a spatial intersection area to form a tool High-directivity close-range fixed-point method for reducing acoustic waves.

The transmission of sound plays an important role in the life of modern people. The combination of sound and picture brings sensory and visual satisfaction to modern people. Based on the modern people's emphasis on personal privacy, it is an important consideration to be able to listen to music without disturbing others or being disturbed by others. In order to achieve the above objectives, many people have built a dedicated audio-visual room in their residence. However, it requires a certain amount of soundproofing equipment or materials, and it is not expensive, and there is not enough space for everyone to build the audio-visual room. Therefore, its application is limited and the convenience of space is insufficient.

In response to the aforementioned problems, people have thought about how to make the transmission of sound direct in a limited space. That is, how to form an audio signal that can be listened to only in a specific area, and the sound signal cannot be heard outside a specific area. This can eliminate the interference of the listener to others or others to the listener. One way is to use ultrasonic waves.

The bandwidth of the ultrasound exceeds the frequency range that the human ear can hear, and it does not affect the human hearing. However, when ultrasonic waves propagate in the air, the high directivity exhibited by the physical action can be utilized. After the voice signal that can be heard by the human ear is modulated and loaded into the ultrasonic wave, the sound signal is collectively transmitted to a specific area based on the high directivity of the ultrasonic wave. During the transmission process, the modulated acoustic wave and the air form a nonlinear interaction (this is called self-demodulation), thereby releasing the audible sound.

The foregoing is self-demodulation in a nonlinear manner by ultrasonic waves in air. After a distance is transmitted, the sound signal is demodulated from the ultrasonic wave (carrier) and restored to an audible signal of the human ear. Conventionally, in order to achieve effects such as undistorted sound, higher directivity, and longer transmission distance, a large number of transmitting elements are required to concentrate the ultrasonic carrier. In addition, since self-demodulation is achieved by relying on an air medium, it takes a certain distance to achieve sufficient degree of demodulation. That is, the foregoing method is not suitable for applications in close-closed spaces. Moreover, a large number of transmitting components are not only disadvantageous for small spaces, but also greatly increase manufacturing costs. If space and cost considerations reduce the use of transmitting components, it is bound to compromise the distortion of the sound, which in turn affects the quality of the restored sound.

For the foregoing reasons, conventional techniques are unable to form a reduced sound signal at close range. In any case, the need to listen to music in a close-closed space without interference from others is increasing with increasing emphasis on personal privacy. As a result, there is still a need for a method or apparatus for listening to sound in a close enclosed space.

In particular, the present invention provides a method and apparatus for forming a close-range fixed-point reduction sound wave. The system uses at least two high-frequency carrier signals to respectively load audio signals to form a plurality of The load signals are loaded, and the load signals are coincident in a spatial intersection area to form a close-range fixed-point restoration sound wave. The close-range fixed-point reduction sound waves formed by such methods and devices are highly directional, so that the listener can listen to music signals in the space intersection area without being affected by the surrounding environment.

In an embodiment, the present invention provides a method for forming a close-range fixed-point restored sound wave, comprising: generating at least one audio signal; and generating at least two high-frequency carrier signals corresponding to the audio signal, wherein the audio signals are respectively loaded. And corresponding to each of the high-frequency carrier signals to form at least two load signals; wherein the load signals are respectively sent to a spatial intersection area to form a close-range fixed-point restored sound wave, and the high-frequency carrier signals overlap to form a coincidence The high frequency carrier signal has a frequency higher than the frequency of the original high frequency carrier signal, and the amplitude of the coincident high frequency carrier signal is smaller than the amplitude of the original high frequency carrier signal.

In the above-described method for forming a close-range fixed-point restored sound wave, the frequency of the high-frequency carrier signal is 16 kHz or more. The preferred number of audio signals is the same as the number of high frequency carrier signals. There may be two or more audio signals, and there is substantially no phase difference between the audio signals.

The high-frequency carrier signal is superimposed so that the high-frequency carrier signals overlap each other in the spatial intersection region with the positive and negative half cycles of the high-frequency carrier signal to form a close-range fixed-point restored sound wave. Alternatively, the high-frequency carrier signal uses a modulation method such that the high-frequency carrier signals are in a spatial intersection region so that the high-frequency carrier signals overlap each other in a phase difference manner to form a close-range fixed-point restored sound wave.

In the above method for forming a close-range fixed-point restored sound wave, if the number of high-frequency carrier signals is n, the preferred phase difference of each high-frequency carrier signal is 360/n degrees. In addition, each The amplitude difference between the high frequency carrier signals can be less than 50%. Preferably, the amplitude difference between each high frequency carrier signal is between 0 and 20%. The frequencies between the high frequency carrier signals are the same and have a phase difference. The number of load signals is n, and the preferred phase difference between the load signals is 360/n degrees. The loading signal is sent in a positive or negative half cycle. In addition, if the number of high frequency carrier signals is n, the frequency of the high frequency carrier signals is n times the original high frequency carrier signals.

In another embodiment, the present invention provides a close range fixed point acoustic wave device comprising at least two modulators or adders and a plurality of directional transmitters. The modulator or adder is configured to load the at least one audio signal into the high frequency carrier signals of the at least two corresponding audio signals, and generate at least two load signals, wherein each of the high frequency carrier signals has a phase difference. A plurality of directional transmitters are respectively configured to receive the loading signal and send the loading signal in the direction of the spatial intersection area where the sound wave is expected to be restored. The load signal is separately transmitted by the directional transmitter, and then combined and restored in a spatial intersection area to form a close-range fixed-point restored sound wave. The close-range fixed-point restored sound wave includes at least one coincident high-frequency carrier signal and a coincident audio signal, and the coincidence is high. The frequency of the frequency carrier signal is greater than the frequency of the original high frequency carrier signals, and the amplitude of the coincident high frequency carrier signal is smaller than the amplitude of the original high frequency carrier signals.

The foregoing short-range fixed-point reduction acoustic wave device further includes at least two amplifiers connected to the modulator and used to amplify the loading signal and output to the directional transmitter. Each load signal is sent in a difference between positive and negative half cycles. The ideal phase difference between the high frequency carrier signals is 120 degrees. The number of the loading signals can be three, and the ideal phase difference between the loading signals is 120 degrees. If the number of the loading signals is n, the ideal phase difference between the loading signals is 360/n degrees. In addition, if the number of high frequency carrier signals is n, the frequency of the high frequency carrier signals is n times the original high frequency carrier signals.

In still another embodiment, the present invention provides another proximity fixed point reduction acoustic wave device comprising a positioning device, at least two modulators, and at least two tracking directional transmitters. The at least two modulators are configured to load the at least one audio signal into the high frequency carrier signals of the at least two corresponding audio signals, and generate at least two loading signals, wherein each of the high frequency carrier signals has a phase difference. At least two tracking directional transmitters are used to track the positioning device and follow the positioning device to send a loading signal thereto. The load signal is separately transmitted by the directional transmitter, and then combined and restored in a spatial intersection area to form a close-range fixed-point restored sound wave; the high-frequency carrier signals overlap to form a coincident high-frequency carrier signal, and the frequency of the high-frequency carrier signal is overlapped. It is greater than the frequency of the original high frequency carrier signals, and the amplitude of the coincident high frequency carrier signals is smaller than the amplitude of the original high frequency carrier signals.

S101~S104‧‧‧Steps

200‧‧‧Close-range fixed point acoustic wave device

201‧‧‧ modulator

202‧‧‧Transformer

203‧‧‧Transformer

204‧‧‧Directive Transmitter

205‧‧‧Directive Transmitter

206‧‧‧Directive Transmitter

300‧‧‧Close-range fixed point acoustic wave device

400‧‧‧Close-range fixed point acoustic wave device

401‧‧‧Tracking Directional Transmitter

402‧‧‧Tracking Directional Transmitter

403‧‧‧ Positioning device

S1‧‧‧High frequency carrier signal

S2‧‧‧High frequency carrier signal

S3‧‧‧High frequency carrier signal

S4‧‧‧ coincidence high frequency carrier signal

A1‧‧‧High frequency carrier signal

A2‧‧‧High frequency carrier signal

A3‧‧‧High frequency carrier signal

B1‧‧‧Audio signal

B2‧‧‧Audio signal

B3‧‧‧Audio signal

C‧‧‧ Close-range fixed-point restoration of sound waves

E‧‧‧ Space Intersection Area

1 is a schematic flow chart showing a method for forming a short-distance fixed-point reduction sound wave according to an embodiment of the present invention; and FIG. 2 is a diagram showing a method for superimposing or modulating a high-frequency carrier signal according to the method shown in FIG. FIG. 3 is a schematic diagram showing a close-range fixed-point reduction acoustic wave device according to another embodiment of the present invention; and FIG. 4 is a schematic diagram showing a close-range fixed-point reduction acoustic wave according to another embodiment of the present invention; Schematic diagram of the device; FIG. 5 is a schematic view showing a short-distance fixed-point reduction acoustic wave device according to still another embodiment of the present invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. For the sake of clarity, many practical details will be explained in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not necessary. In addition, some of the conventional structures and elements are illustrated in the drawings in a simplified schematic manner, and the repeated elements may be represented by the same reference numerals.

Please refer to FIG. 1 . FIG. 1 is a schematic flow chart of a method for forming a short-distance fixed-point reduction sound wave according to an embodiment of the invention.

In an embodiment, the method for forming a close-range fixed-point restored sound wave substantially comprises the following steps: S101, generating at least one audio signal.

S102. Generate at least two high frequency carrier signals corresponding to the audio signals.

S103. The audio signals are respectively loaded to the corresponding high frequency carrier signals to form at least two load signals.

S104, each of the two loading signals is sent to a spatial intersection area to form a close-range fixed-point restored sound wave, wherein the high-frequency carrier signals overlap to form a coincident high-frequency carrier signal, and the frequency of the coincident high-frequency carrier signals is greater than the original High frequency carrier The frequency of the signal, and the amplitude of the coincident high frequency carrier signal is smaller than the amplitude of the original high frequency carrier signal.

In the foregoing step S103, the high frequency carrier signal is an ultrasonic signal having a frequency of 16 kHz or more. Generally, this high-frequency carrier signal cannot be heard by the human ear, and its frequency, amplitude or phase characteristics are different from those of the audio signal. In order for the audio signal to be loaded to the high frequency carrier signal, the audio signal is superimposed or modulated.

In the foregoing step S104, in order to restore the original audio signal by the loading signal in the intersection overlapping area to form a close-range fixed-point restored sound wave, the high-frequency carrier signal is transmitted in a superimposed manner so that the high-frequency carrier signals are in a spatial intersection area with a high-frequency carrier signal. The positive and negative half-cycles coincide; or through the modulation method, the high-frequency carrier signals are in the spatial intersection area so that the high-frequency carrier signals overlap each other in a phase difference manner. The superposition or modulation of the aforementioned high frequency carrier signals will be described in detail later in FIG.

In the method for forming a close-range fixed-point restored sound wave, the number of audio signals and the number of high-frequency carrier signals can be freely selected. Preferably, the number of audio signals can be selected to be the same as the number of high-frequency carrier signals, thereby providing a signal-to-noise ratio. Large difference, low noise signal.

The foregoing audio signals may be two or more, and preferably, there is substantially no phase difference (less than |90 |°) between the audio signals. The selection of the phase difference is based on the fact that if the phase difference is zero degrees, constructive interference occurs in each audio signal. If a phase difference is formed, the audio signals form destructive interference and cause sound distortion.

Each of the aforementioned high frequency carrier signals has the same frequency and a phase difference. Preferably, if the number of high frequency carrier signals is n, and the phase difference of each high frequency carrier signal is 360/n degrees. Thereby, the purpose of attenuating the high frequency can be achieved, and the frequency amplitude of the high frequency carrier signal is superposed.

The amplitude difference between each of the aforementioned high frequency carrier signals is less than 50%. Preferably, the amplitude difference between each high frequency carrier signal is between 0 and 20%. Thereby, the purpose of attenuating the high frequency can be achieved, and the frequency amplitude of the high frequency carrier signal is superposed.

The load signals are transmitted between each other with a phase difference or a difference between positive and negative half cycles to obtain a close-range fixed-point restored sound wave. The loading signal can be selected according to the appropriate number, and the phase difference of each loading signal is modulated according to the selected quantity to enable the original audio signal to be better restored. Preferably, if the number of load signals is n, the phase difference between the load signals is selected to be 360/n degrees. Thereby, the purpose of attenuating the high frequency can be achieved, and the frequency amplitude of the high frequency carrier signal is superposed.

When the number of the high frequency carrier signals is n, the frequency of the high frequency carrier signals is n times of the original high frequency carrier signals.

Please refer to FIG. 2 . FIG. 2 is a schematic diagram showing the method of forming a close-range fixed-point restored sound wave by superimposing or modulating the high-frequency carrier signal according to the method shown in FIG. 1 . It is worth mentioning that the present invention does not use the characteristics of self-demodulation of high frequency carrier signals (such as ultrasonic waves) to recover sound waves in the air, but restores the sound waves by modulating the characteristics of the high frequency carrier signals themselves. As illustrated in FIG. 2, the modulated high frequency carrier signal S1, the high frequency carrier signal S2, and the high frequency carrier signal S3 have the same frequency and phase difference. After the high frequency carrier signal S1, the high frequency carrier signal S2 and the high frequency carrier signal S3 are superimposed and superimposed, a high frequency carrier signal S4 is formed. Coincidence of high frequency carrier signals based on the principle of constructive interference or destructive interference of fluctuations The frequency of S4 is greater than the frequency of the original high frequency carrier signals, and the amplitude of the coincident high frequency carrier signals is smaller than the amplitude of the original high frequency carrier signals. The difference between the positive and negative half cycles mentioned above is that when the waveform is superimposed, the loading signal can be more effectively delivered to the spatial intersection area.

Please refer to FIG. 3 and FIG. 4 . FIG. 3 is a schematic diagram of a close-range fixed-point reduction acoustic wave device 200 according to another embodiment of the present invention; FIG. 4 is a schematic diagram of a close-range fixed point according to still another embodiment of the present invention. A schematic diagram of the acoustic wave device 300 is restored. The method of forming a close-range fixed-point acoustic wave has been described above, and the description of the physical structure will be followed by the following, so that the present invention can be more clearly understood.

In Fig. 3, the close-range fixed point reduction acoustic wave device 200 includes at least two modulators 201, 202 and two directional transmitters 204, 205. The modulator 201 is configured to receive the high frequency carrier signal A1 and the audio signal B1, and then the audio signal B1 is modulated or superimposed and then loaded into the high frequency carrier signal A1 to form a loading signal. Similarly, the modulator 202 is configured to receive the high frequency carrier signal A2 and the audio signal B2, and then the audio signal B2 is modulated or superimposed and then loaded into the high frequency carrier signal A2 to form another loading signal. Signal B1 and audio signal B2 are sent from the same audio source. The two loading signals are respectively sent to a spatial intersection area E via the directional transmitters 204 and 205 to form a close-range fixed-point restored sound wave C. The waveform is as shown by the number C in FIG. As mentioned in the foregoing method, the high frequency carrier signal A1 and the high frequency carrier signal A2 have the same frequency and have a phase difference, and the loaded signals after the respective loading are transmitted in a difference between positive and negative half cycles. Thereby, it is possible to control the reduction of the specific distance to form an audible close-range fixed-point restored sound wave C, which is heard by the listener located in the spatial intersection area E. Based on the nonlinear physical characteristics of the high-frequency carrier signal A1 and the high-frequency carrier signal A2, the close-range fixed-point restored sound wave C is formed in a close proximity of the listener to the directional transmitters 204, 205. Closed-minimum area; based on the high directivity of the high-frequency carrier signal A1 and the high-frequency carrier signal A2, the resulting close-range fixed-point restored sound wave C is only heard by the listener located in the space intersection area E, without being Passed to the space intersection area E, so that others can not hear the close distance fixed point to restore the sound wave C, to achieve anti-interference effect. Further, the fixed-point restored sound wave C includes at least one coincident high-frequency carrier signal S4 and one of the superimposed audio signals superimposed by the audio signals B1 and B2. It should be noted that the audio signal B1 and the audio signal B2 are emitted from the same audio signal source. The frequency of the coincident high frequency carrier signal S4 is greater than the frequency of the original high frequency carrier signals A1 and A2, and the amplitude of the coincident high frequency carrier signal S4 is smaller than the amplitude of the original high frequency carrier signals A1 and A2; preferably, if When the number of high frequency carrier signals is n, the frequency of the high frequency carrier signal S4 is n times the original high frequency carrier signals A1 and A2.

In the aforementioned close-range fixed-point reduction acoustic wave device 200, the modulators 201, 202 may also be replaced with an adder. Moreover, it is also possible to use amplifiers to be coupled to the modulators 201, 202, respectively, and to transmit the amplified load signals to the directional transmitters 204, 205, respectively.

Please continue to refer to Figure 4. In Fig. 4, the use of a plurality of directional transmitters 204, 205, 206 enables the close-range fixed-point restoration of sound waves C to be better restored, and the listener can hear sound signals having better directivity and less distortion. Accordingly, in the close-range fixed-point reduction acoustic wave device 300 disclosed in FIG. 4, the difference from the above-described short-range fixed-point reduction acoustic wave device 200 is that a modulator 203 and a directional transmitter 206 are provided in multiple groups.

The close-range fixed point reduction acoustic wave device 300 includes three modulators 201, 202, 203, and three directional transmitters 204, 205, 206. Through this configuration mode, the audio signal B1 is loaded into the high frequency carrier signal A1 through the modulator 201 to form a loading signal. The audio signal B2 is loaded into the high frequency carrier signal A2 through the modulator 202 to form another loading signal; and the audio signal B3 is loaded into the high frequency carrier signal A3 through the modulator 203 to form a further loading signal. The three load signals are each sent to the directional transmitters 204, 205, 206 and rendezvous to the spatial intersection area E. The directional transmitters 204, 205, 206 are arranged in an array to obtain a better sound reproduction effect.

In the above-mentioned short-range fixed-point reduction acoustic wave devices 200 and 300, the number of high-frequency carrier signals and audio signals can be changed according to actual situation requirements, and the phase difference between each high-frequency carrier signal or each load signal can be preferably selected. For example, if the number of high frequency carrier signals is n, the phase difference of each high frequency carrier signal is 360/n degrees; when the number of loading signals is n, the phase difference of each loaded signal is 360/n degrees. Through this phase difference selection method, the sound reproduction can be made more accurate and not distorted.

Please refer to Figure 5. FIG. 5 is a schematic diagram showing a close-range fixed-point reduction acoustic wave device 400 according to still another embodiment of the present invention. In the close-range fixed point reduction acoustic wave device 400, the same modulators 201, 202 as in the previous embodiment are used. The difference is matched with the tracking directional transmitters 401, 402; and the viewer is equipped with the positioning device 403. According to this, when the listener moves, the close-range fixed-point restoration sound wave C also moves, so that the listener can hear the directional and undistorted sound signals everywhere, without disturbing others or disturbing others.

In summary, the short-distance fixed-point reduction acoustic wave forming method and apparatus provided by the present invention can form a closed listening space at a short distance, free from external interference or interference with the outside world. It has many things, such as: watching movies in the middle of the night does not affect other people's work; there are multiple music playback systems in the same space without interfering with each other; it can be clear in noisy environments. Appreciate the music; and when answering the call, the same passenger can not hear the other party's call content.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

S101~S104‧‧‧Steps

Claims (20)

A method for forming a close-range fixed-point restored sound wave, comprising: generating at least one audio signal; and generating at least two high-frequency carrier signals corresponding to the audio signals, wherein the audio signals are respectively loaded to the corresponding high-frequency carrier signals to form At least two load signals; wherein the load signals are respectively sent to a spatial intersection area to form a close-range fixed-point restored sound wave, and the high-frequency carrier signals are coincident to form a coincident high-frequency carrier signal; wherein the coincidence is high The frequency of the frequency carrier signal is greater than the frequency of the original high frequency carrier signal, and the amplitude of the coincident high frequency carrier signal is smaller than the amplitude of the original high frequency carrier signal. The method for forming a close-range fixed-point reduction sound wave according to claim 1, wherein the frequency of the high-frequency carrier signals is 16 kHz or more. The method for forming a short-distance fixed-point reduction sound wave according to claim 1, wherein the high-frequency carrier signals use a superposition manner, so that the high-frequency carrier signals are in the spatial intersection area with the high-frequency carriers. The positive and negative half of the signal coincide to form the close-range fixed-point restored sound wave. The method for forming a close-range fixed-point reduction sound wave according to claim 1, wherein the high-frequency carrier signals use a modulation method, so that the high-frequency carrier signals are in the space intersection area to make the high The frequency carrier signals are overlapped with each other to form the close-range fixed-point restored sound wave. The method for forming a close-range fixed-point restored sound wave according to claim 1, wherein the number of the audio signals is the same as the number of high-frequency carrier signals. The method for forming a close-range fixed-point restored sound wave according to claim 1, wherein the audio signal is two or more and each of the audio signals does not have a phase difference. The method for forming a close-range fixed-point restored sound wave according to claim 1, wherein the number of the high-frequency carrier signals is n, and the phase difference of each of the high-frequency carrier signals is 360/n degrees. The short-distance fixed-point reduction acoustic wave forming method according to claim 1, wherein the amplitude difference between the high-frequency carrier signals is between 0 and 20%. The method for forming a close-range fixed-point reduction sound wave according to claim 1, wherein the number of the high-frequency carrier signals is n, and the frequency of the coincident high-frequency carrier signals is n times of the original high-frequency carrier signals. The short-distance fixed-point reduction acoustic wave forming method according to claim 1, wherein each of the high-frequency carrier signals has the same frequency and a phase difference. The method for forming a close-range fixed-point reduction sound wave according to claim 1, wherein the number of the loading signals is three or more. The method for forming a close-range fixed-point reduction sound wave according to claim 1, wherein the loading signal is sent in a difference between positive and negative half cycles. A short-range fixed-point reduction acoustic wave device, comprising: at least two modulators or adders for loading at least one audio signal into at least two high-frequency carrier signals corresponding to the audio signals, and generating at least two loading signals And each of the high frequency carrier signals has a phase difference; and a plurality of directional transmitters for respectively receiving the loading signals, and transmitting the loading signals in a direction of a spatial intersection area of the intended sound wave reduction; wherein After being loaded by the directional transmitters, the loading signals are combined and restored in a spatial rendezvous region to form a close-range fixed-point restored acoustic wave, and the close-range fixed-point restored acoustic wave includes at least one coincident high-frequency carrier signal and a coincident audio signal, and The frequency of the coincident high frequency carrier signal is greater than the frequency of the original high frequency carrier signal, and the amplitude of the coincident high frequency carrier signal is smaller than the amplitude of the original high frequency carrier signal. The short-distance fixed-point reduction acoustic wave device of claim 13, further comprising at least two amplifiers, wherein the amplifiers are connected to the modulators for amplifying the loading signals and outputting to the directional transmitters . The near-range fixed-point reduction acoustic wave device according to claim 13, wherein each of the loading signals is sent in a difference between positive and negative half cycles. The near-range fixed-point reduction acoustic wave device according to claim 13, wherein the frequency of the high-frequency carrier signals is 16 kHz or more. The near-range fixed-point reduction acoustic wave device according to claim 13, wherein the number of the loading signals is 3 or more. The short-range fixed-point reduction acoustic wave device according to claim 13, wherein the number of the high-frequency carrier signals is n, and the phase difference of each of the high-frequency carrier signals is 360/n degrees. The short-range fixed-point reduction acoustic wave device according to claim 13, wherein the number of the high-frequency carrier signals is n, and the frequency of the coincident high-frequency carrier signals is n times of the original high-frequency carrier signals. A short-range fixed-point reduction acoustic wave device, comprising: a positioning device; at least two modulators for loading at least one audio signal to at least two high-frequency carrier signals corresponding to the audio signal, and generating at least two loading signals, wherein each Having a phase difference between the high frequency carrier signals; and at least two tracking directional transmitters for tracking the positioning device and transmitting the loading signals thereto along the positioning device; wherein the loading signals pass the pointing signals After being sent separately, the transmitters are combined and restored in a spatial rendezvous region to form a close-range fixed-point restored sound wave; the high-frequency carrier signals are superposed to form a coincident high-frequency carrier signal, and the frequency of the coincident high-frequency carrier signals is greater than the original The frequency of the high frequency carrier signal, and the amplitude of the coincident high frequency carrier signal is smaller than the amplitude of the original high frequency carrier signal.